Medications for Huntington s Disease Vicki Wheelock, M.D. Director, HDSA Center of Excellence at UC Davis June 4, 2013
Outline Introduction and disclaimers Medications for cognitive symptoms Medications for psychiatric symptoms Medications for sleep difficulties Medications for juvenile HD Medications for chorea and dystonia Conclusions
Introduction HD symptoms include cognitive impairment, chorea and movement difficulties, and psychiatric challenges. This session will review the indications, benefits and side effects of medications which are commonly used to manage these symptoms. It is extremely important to recognize that behavioral techniques, counseling, speech, occupational and physical therapies and adaptive equipment are the primary forms of treatment for many HD symptoms.
There is only one medication that is FDA approved for HD That drug is tetrabenazine (Xenazine). Many other drugs approved for other indications (depression, psychosis, Parkinson s disease, Alzheimer s disease) have been tried and may be used for HD. This is called off-label prescribing. In some cases, there are research studies that support use of these medications in HD. As with all medications, HD patients must be monitored for side effects. There is a great need for additional drugs and more studies. Please refer to A Physician s Guide to the Management of HD, 3rd edition for guidance.
The relationship between HD symptoms and age From: Harper, PS. Huntington s disease Presenting motor findings Symptoms in HD Chorea Rigidity Bradykinesia Juvenile HD 0 10 20 30 40 50 60 70 Age in years at HD onset
Cognitive Impairments in HD Learning and memory Perceptual skills Unawareness Language difficulties Executive dysfunction Speed of processing Attention and concentration Planning and organization Lack of initiation Perseveration: getting stuck Impulsivity
Medications for Cognitive Difficulties We sometimes prescribe drugs for from Alzheimer s disease. Those are best for memory and perhaps perceptual skills. No benefit for executive dysfunction. Donepezil, 5-10 mg daily may be tried not effective in one randomized trial. Rivastigmine 6 mg per day studied in open-label trial in Europe; showed possible benefit. Needs additional study. Memantine: Pilot trial in 2009 showed no benefit for cognition. Latrepirdine (Dimebon) looked promising in Phase 2 trial, but failed in Phase 3 trial to improve cognition. 1. Neurology 2006;67:1268 1271 2. Parkinsonism and Rel Disord 13 (2007) 453 454 3. Arch Neurol. 2010;67(2):154-160
Medications for Cognitive Difficulties Dysexecutive function: Trial of atomoxetine failed to help with attention and executive function (J Paulson, 2009) Apathy and lack of initiation may respond to stimulant drugs such as methyphenidate, pemoline, or dextro-amphetamine (see Rosenblatt, A Physician s Guide to the Management of HD, 3rd edition). Apathy may worsen with sedating drugs such as anti-psychotics or benzodiazepines
Medications for Depression Class Trade Name Generic Name Selective Seratonin Reuptake Inhibitors (SSRIs) Zoloft Celexa Lexapro Paxil Prozac Non-selective Serotonin Reuptake Inhibitors (NSRIs) Welbutrin Effexor Sertaline Citalopram Escitalopram Paroxetine Fluoxetin Buproprion Venlafaxine Other Remeron Mirtazeprine Side effects: well-tolerated. Occasional stomach upset, dizziness, sleepiness, sexual dysfunction; withdrawal syndrome for Paroxetine.
Medications for Anxiety Class Trade Name Generic Name Selective Seratonin Reuptake Inhibitors (SSRIs) Zoloft Celexa Lexapro Paxil Prozac Sertaline Citalopram Escitalopram Paroxetine Fluoxetin Benzodiazepines Klonopin Clonozepam Non-benzodiazepine anxiolytic Buspar Buspirone Side effects: well-tolerated. Occasional stomach upset, dizziness, sleepiness, sexual dysfunction; withdrawal syndrome for Paroxetine.
Medications for Psychosis Class Trade Name Generic Name Side Effects Atypical neuroleptics (newer agents) Zyprexa Olanzepine Seroquel Quetiapine Geodon Ziprasidone Abilify Aripiprazole Typical neuroleptics (older agents) Haldol Haloperidol Prolixin Fluphenzine Risperdal Risperidone Weight gain, sedation, metabolic syndrome, possible parkinsonism Parkinsonism, tardive dyskinesia, sedation
Medications for Mania Class Trade Name Generic Name Side Effects Anti-epileptic drugs Neuroleptic drugs Depakote Divalproex sodium Weight gain, liver toxicity Lamictal Lamotrigine Skin rash, possibly fatal Topamax Tegretol Topiramate Carbamazepine Memory impairment, kidney stones Bone marrow suppression, skin rash Many; depends on severity of symptoms. Major sedation, May need injectable medication. parkinsonism
Medications for Obsessive-Compulsive Disorder SSRI antidepressants (see slide 9) For severe cases, neuroleptics may be necessary (see slide 11)
Medications for Irritability Behavioral strategies are always first-line Medications can be considered if behavioral strategies are not adequate SSRI drugs such as sertraline, fluoxetine, paroxetine Benzodiazepines (clonazepam) Anti-epileptic drugs such as Depakote Rarely, neuroleptics
Insomnia in HD First, try sleep hygiene Go to bed at night, get up in the morning Limit caffeine to no more than 1-2 cups before noontime Limit or eliminate alcohol Regular exercise, early in the day Quiet night-time activities before bed no computer If this fails, Avoid sedatives like Ambien, Lunesta, benzodiazepines, etc: use only on occasion. Melatonin may help people get to sleep and is safe Antidepressants: trazodone,mirtazepine Occasional use of neuroleptic quetiapine
Treating Juvenile HD Medications for cognition and school performance not recommended Medications for psychiatric symptoms may occasionally be needed. Consult a Child Psychiatrist. Movement-related problems are usually different than in adults: slowness, rigidity and dystonia are most common Some may have chorea Seizures may occur in JHD
Juvenile Onset HD: Rigidity Class Trade Name Generic Name Side Effects Benzodiazepines Valium Diazepam Sedation Klonopin Clonazepam Sedation Anti-spasticity Lioresal Baclofen Sedation Zanaflex Tizanidine Sedation Anti-parkinson agents Symmetrel Amantadine Hallucinations Sinemet Carbidopa-levodopa Hallucinations
Juvenile Onset HD: Anti-seizure Medications Trade Name Generic Name Side Effects Keppra Levetiracetam Sedation Depakote Divalproex sodium Stomach upset, liver toxicity Tegretol Carbamazepine Bone marrow depression, skin rash Dilantin Phenytoin Sedation, gum disease Klonopin Clonazepam Sedation Many others will depend on seizure type
Adult-onset HD: Chorea is a difficult symptom Affects nearly all adult HD patients (progressively disabling) Reduces employability Contributes to social isolation and stigmatization Presents an increased safety risk (falling, worsened gait, need for supervision) Contributes to weight loss Can lead to injury and make caregiving difficult, especially in late-stage HD
Tetrabenazine: First drug for the treatment of Huntington s disease to receive FDA approval (TETRA study) Double-blind, placebo-controlled study of tetrabenazine in manifest HD 84 people with HD, randomized 2:1 to tetrabenazine or placebo for 12 weeks Primary endpoint: chorea score
TETRA Study Results
Tetrabenazine Benefits: Reduces chorea Side effects: Swallow dysfunction Depression/Suicide Restlessness Interactions: Some anti-depressants Other anti-chorea drugs Dosing: Genetic test Monitor EKG Cost: Special program
Tetrabenazine and Depression 20% of TETRA participants had new or worsening depression Patients, their caregivers, and families are informed of the risks of depression. Monitor the patient for any new or worsening symptoms of depression Seek help immediately if the patient develops thoughts of suicide Sometimes dosage reduction will help If depression or suicidal thoughts don t respond to dose reduction, then tetrabenazine must be discontinued.
Medications for Chorea First-line: Tetrabenazine (FDA-approved in 2008 as the first drug in US for HD) Second line: benzodiazepines Third line: antipsychotic drugs Typical (older): haloperidol, fluphenazine Atypical (newer): olanzapine, risperidone, others
Anti-Chorea Medications In patients with significant psychiatric disturbances (severe depression, mania, anger outbursts or psychosis), neuroleptic drugs made be first-choice because they will treat both the psychiatric symptoms and reduce chorea. Atypical neuroleptics work well for both psychiatric symptoms and chorea, except for quetiapine, which doesn t help chorea. (See slide 11 for details)
Further Recommendations about Treatment of Chorea Anti-chorea therapy should be re-evaluated at least annually. Some patients will require increasing doses of anti-chorea medications over time. Some may even require the addition of two or more drugs to control chorea. Many will eventually develop increasing dystonia and rigidity with HD progression, necessitating reduction or cessation of anti-chorea medications.
10% of adults have the rigid-dystonic form of HD. Treating rigidity: Class Trade Name Generic Name Benzodiazepines Valium Klonopin Anti-spasticity Lioresal Zanaflex Anti-parkinson agents Symmetrel Sinemet Requip, Mirapex Diazepam Clonazepam Baclofen Tizanidine Amantadine Carbidopa/Levodopa Ropinirole, pramipexole Tetrabenazine is not indicated for patients with rigid-dystonic HD.
Treating Dystonia in HD Class Trade Name Generic Name Benzodiazepine Klonopin Anti-spasticity Lioresal Zanaflex Anticholinergics Artane, others Chemodenervation Botox, others Anti-parkinson agents Symmetrel Sinemet Clonazepam Baclofen Tizanidine Trihexyphenidyl Botulinum toxin Amantadine Carbidopa/Levodopa Tetrabenazine is not indicated for patients with rigid-dystonic HD.
Concluding Thoughts Behavioral strategies, speech therapy, physical therapy, counseling lifestyle changes are important tools in helping to treat HD. The only medication for HD that is FDA-approved is tetrabenazine, but many others have been used successfully on an off-label basis. All medications have side effects, and selecting the right medication should be individualized for each HD patient. All medications should be re-evaluated periodically as HD symptoms change or progress.